Elastic-fluid turbine



Dec. 30, 1930. L. c. FLETCHER ELASTIC FLUID TURBINE Filed Sept. 25, 1929INVENTOR LG- FLETCHER ov. @a.

ATTORNEY Patented Dec. 30, 1930 UNITED STATES PATEI' .OFFICE LINnsEY c.FLETCHER, F 'IVIOORES, PENNSYLVANIA, ASSIGNOR 'ro WESTINGHOUSE ELECTRIC& MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA ELASTIC-FLUIDTURBINE Application filed September 25, 1929. Serial No. 395,086.

My invention relates to an elastic fluid turbine, more particularly to aturbine having, in the initial or only stage, a set of expansion nozzlesand admission valve means therefor 5 designed for relatively lightloads, and having a second set of expansion nozzles in said stage andadmission valve means therefor designed for relatively greater loads,andit has for its object to provide mechanism whereby either of saidvalve means may be opened by the turbine governor. I A further object isto provide mechanism of the character set forth whereby either, but notboth, of said valves may be fully opened by the governor.

The above and other'objects are effected by my invention, as will beapparent from-the following description and claims taken in connectionwith the accompanying drawing,

forming a part of this application, in which: The single figure is aview, partly in section and partly in elevation, of apparatus em bodyingmy invention.

Referring to the drawing more in detail, I

2 show an elastic fluid turbine indicated generally at 10. This'turbineembodies, either as the single stage of the turbine or as the initialstage, an impulse stage including arow of blades 11 carriedby the rotor12, and nozzles 13 for directing motive fluid against the moving blades11. The nozzles are divided into ,two sets, one set consisting of agroup of nozzles 14 controlled by a valve 15 and a second group ofnozzles 16 controlled by a valve 17 The other set consists of a group ofnozzles 18 controlled by a valve 19 and a second group of nozzles 20controlled by a valve 21. by The nozzles in the groups 14 and 16 are designed to provide maximum efficiency at relatively light loads. Theyare, therefore, de-

. V signed for relatively small steam flow, and for greater expansionratios. The nozzles in the groups 18.and 20 are greater in number topass greater quantities of steam, and their expansion ratios are less.They are therefore designed for greatest efliciency at the higher loads.

The stems of the valves 15 and 17 are connected to a lever 22 adjacentthe opposite ends thereof, and the stems of the valves 19 and 21 arelikewise connected to a similar lever 23 at If its ends. A lever 24 isprovided for control- I ling the levers 22 and 23, one end, 25 of thelever 24 being connected to the lever 22 inter mediate the'ends of thelatter, and the other end, 26, being connected to the lever 23intermediate its ends.

A spring 27is connected to the lever 22 near the stem of the valve 17,and an abutment 28 limits upward movement of the end of the leverconnected to the valve 15, so that, upon upward movement of the lever 22by the lever 24, the valve 15 is first moved in opening direction untilthe lever strikes the abutment 28, after which the valve 15 is openedagainst the force of the spring 27 A spring 29 is likewise connected tothe lever 23 near the valve stem of the valve 21 anda similar abutmenttothespeed of the turbine, or to any other operating condition inresponse to which it is desired to control the admission of motive fluidto the turbine, and may include power actuating mechanism as is wellunderstood in the art.

. At 34 is shown a lever whichis pivoted at 35. This lever has one end36, which is adapted to abut the end 25 of the lever 24 when rotated tothe left, and a second end 37 whichis adapted to abut the end 26v of thelever 24 when rotated to the right. The lever 34 is rotated about thepivot 35 by means of a worm 38 meshing with a gear sector 39 carried bythe lever 34. A hand wheel 40 or other suitable means may be providedfor rotating the worm 38.

The operation of the above described embodiment is as follows:

vAssume that it is desired to carry a relatively light load. The worm 38is operated to rotate the lever 34' inclockwise direction until the end37 thereof abuts the end 26 of the lever 24 at its lowermost position,thereby retaining the valves 19 and 21 in closed position. The operationof the governor 33 in the direction for providing motive fluid admissionis transmitted through the le ver 30 and the link 31 to move the lever24 upwardly at the central point thereof. a The end 26 of the lever 24being held stationary, this upward movement istransmitted to the end 25,which, in turn, raises the lever 22. The lever 22 thereupon opens thevalve-15 to admitmotive fluid to the group of nozzles it until the endotthe lever strikes the end otthe abut ment 28, whereupon the other end ofthe lever '22 is raised to open the valve 17.

VVhen it is desired to operate at greater loads than can be carried bythe groups of nozzles I l and 16,- the lever 34 is rotated incounter-clockwise direction to retain the end 25 of the lever 24 in itslowermost position, maintaining the valves 15 and 17 in closed position.The upward'movement of the central point of the lever 24: transmittedfrom the governor mechanism is thus transmitted to the end 25. Thecentral point of the lever 23 is thereupon raised eflecting firstopening movement of the admission valve 19 and then opening of-theadmission valve 21. Motive fluid is thus conveyed to the groups ofnozzles 18 and 21, which are designed for effective utilization-ofmotive fluid for higher loads.

From the above description, it will be seen that I have provided one setof nozzles and valve means which are'designed to secure the mosteflicient utilization of motive fluid at relatively light loads, and asecond set of nozzles and valve means therefor for securing the mosteflicient utilization of motive fluid at greater loads. It will also beseen that I have provided mechanism whereby the governing mechanism mayselectively operate the valve means of either set of nozzles.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications, without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are imposed by the prior art or as are specificallyset forth in the appended claims.

What I claim is:

1. The combination with an elastic fluid turbine having one set ofnozzles designed for greatest etliciency at relatively light loads and asecond set of nozzles designed for greatest :Scribed my name this 13thber, 1929.

etlicienc'y at relatively heavy loads, of means for selectivelyadmitting motive fluid to either of said sets of nozzles and shuttingoff admission of motive fluid to the other set, and a governingmechanism responsive to an operating condition of the prime mover forgoverning the admission of motive fluid to the set of nozzles to whichadmission is permitted by said means.

2. In a steam chest for an elastic fluid turbine, the combination of afirst valve means adapted to'admit the required amount of motive fluidfor carrying a relatively light load, a second valve means adapted toadmit the required motive fluid for a relatively greater load. 'overnormechanism responsive to the speed of the turbine, and means whereby thegovernor mechanism may be selectively caused to operate eithervalvemeans. 1

3. The combination with an elastic fluid turbine having one set ofnozzles whose expansion ratios are adaptedfor relatively light loads anda second set of nozzles whose nozzle ratios are adapted for relativelygreater loads, of means for controlling the supply of motive fluid tosaid nozzle sets comprising a valve means for each set, governormechanism may be caused to operate "either valve means and the othervalve means held closed. 5. The combination with an elastic fluidturbine having one set of nozzles designed for relatively light loadsand a second set of nozzles designed for a relatively greater load,ofvalve means for the respective sets. a lever, means controlled by theposition of one point o'tsaid lever for-controlling one valve means,means controlled by the position of a second point of said lever forcontrolling the other valve means, governing mechanism for the turbine,means controlled by the governing mechanismtor actuating said lever at athird point and means for holding said lever against movement at eitherthe first-mentioned or the second-mentioned point, whereby the leverwill be tulcrumed at the point which is held and the valve meanscontrolled by the point of the lever not held will be actuated inresponse to control of the governor.

In testimony whereof, I have hereunto subday of Septenr LINDSEY o.FLETCHER.

